The present invention relates to a new and improved construction of a foundry molding machine --hereinafter sometimes conveniently simply referred to abbreviately as a molding machine-- as well as to the use of such molding machine, and which molding machine for the separate simultaneous production of two mold parts possesses two mold units provided with a respective match plate support and a sand filling- and compaction station, the mold units have associated therewith a respective pivoting device incorporating pivotal arms pivotable about substantially vertical shafts in a respective substantially horizontal plane, the pivotal arms carrying mold frames in mold frame holders, and the pivotal arms pivoting the mold frames from the sand filling- and compaction station while rotating the mold frame containing the lower part of the mold through 180.degree. about a substantially horizontal axis into a superimposed position of both mold parts at an assembly or attachment station where both of the mold parts are deposited on top of one another onto a conveyor device or mechanism.
Such general type foundry molding machine has been taught in U.S. Pat. No. 2,325,501. The mold frame holders are constructed as rectangular pivotal frames which at both of their ends engage about the mold frames, the pivotal frames being mounted at a stand or upright to be vertically displaceable at the center of the rectangle and pivotable about the vertical shaft or axis. In the pivotal frames containing the lower part of the mold the mold frames are held in a rotatable frame which is rotatable about a horizontal axis. The mold frames are detachably connected by means of an electromagnetic coupling with the pivotal frames or rotatable frames respectively. This molding machine possesses a number of different drawbacks. The insertion of cores and controlling mold faults or defects can be only carried out with great difficulty with regard to the upper part of the mold. During lowering of the mold-upper part onto the mold-lower part the pivotal frames are also simultaneously lowered onto the mold table. Due to tolerances there thus exist inaccuracies. The utilization and covering of the mold frames is complicated and slows down the working speed of the machine. Also the use of two pivotal frames offset from one another through an angle of 90.degree. does not result in any appreciable improvement in the working speed for the contemplated mode of operation. Moreover, the machine is not suitable for boxless molds.
In French patent No. 1,147,675 there is disclosed a similar foundry molding machine wherein according to a first exemplary embodiment for a boxless mold mold parts are lowered in succession onto a stationary conveyor belt and an ejection plate mounted from above onto the mold parts fixedly holds the mold parts, whereas the mold frames are vertically raised from the mold parts. There are provided two telescopic columns each having a pivotal arm supported at the end of a mold frame, each such pivotal arm can be pivoted back and forth through an angle of 180.degree.. The pivotal arm carrying the lower part of the mold is rotatable about its horizontal axis through an angle of 180.degree.. Once again this machine also possesses the drawback that the insertion of cores and checking for mold defects at the upper part of the mold is difficult. Also, with this arrangement there must be tolerated very small operating or working speeds since for each telescopic column there is only provided one pivotal arm. The provision of more than one pivotal arm is not possible owing to the contemplated arrangement of the sand filling- and compaction station and the guide rails for the vertical guiding of the mold frames.
Both state-of-the-art molding machines possess the drawback that they are not suitable for producing molds composed of three or more mold parts.